The invention relates to a method of placing a column in the hard or rock like bottom of a body of water, said column having a sharp lower edge and a lower portion or foot which is widening downwardly by means of an inclined outer wall, and that after placing the column upon the bottom of the body of water the soil inside the inner wall of the column is removed.
An example of such a column is disclosed in the PCT application WO 87/03026 and it is known to work such a column, after placing it upon the bottom of the sea, into the bottom of the sea by its own weight and by removing soil material present inside the inner wall of the column by means of suction devices having cutters. Due to the fact that the column has a width which increases downwardly, friction of the soil around the outer wall of the column causes little or no problem. The removal of soil at the inner side however is less simple in particular in case said soil is hard, for instance comprises rock-like deposits. Rotating tools having cutting members wear quickly and cannot reach the stony or hard layer below the sharp lower edge. To bring such a column downwardly at the required depth accordingly creates a problem.
Purpose of the invention is to provide an improvement in this respect.